Alan Montemayor, from left; Carye Bye; Gustavo Metzger, 12; Emmanuel Perez, 12; Isabel Perez, 12; and Luke Metzger hold signs Monday outside Whataburger’s San Antonio headquarters at 300 Concord Plaza. The group then delivered a petition signed by more than 50,000 people that originated with environmental groups Environment Texas, Surfrider Foundation’s Texas Coastal Bend Chapter and Care2.com. The petition asks Whataburger to stop its use of polystyrene foam (commonly known as Styrofoam) cups and containers at its restaurants.

Alan Montemayor, from left; Carye Bye; Gustavo Metzger, 12; Emmanuel Perez, 12; Isabel Perez, 12; and Luke Metzger hold signs Monday outside Whataburger’s San Antonio headquarters at 300 Concord Plaza. The group then delivered a petition signed by more than 50,000 people that originated with environmental groups Environment Texas, Surfrider Foundation’s Texas Coastal Bend Chapter and Care2.com. The petition asks Whataburger to stop its use of polystyrene foam (commonly known as Styrofoam) cups and containers at its restaurants.

Activists are pressuring San Antonio-based Whataburger to end its use of foam cups and containers in favor of materials that are friendlier to the environment.

More than 50,000 people have signed a petition calling on the popular fast-food chain to stop using polystyrene foam, commonly known as Styrofoam, in its cups and food containers. The petition was delivered Monday to Whataburger’s San Antonio headquarters and restaurants in Austin and Corpus Christi by representatives for Environment Texas, Surfrider Foundation’s Texas Coastal Bend chapter and Care2.com.

Whataburger, which has more than 800 stores in 10 states, said in a statement it is looking at alternatives to Styrofoam cups “that keep drinks at the right temperature but we have a lot to consider from a quality and supply perspective when meeting our customers’ expectations.”

“In the meantime, we continue to urge customers to properly dispose of our cups,” the company said.

Polystyrene doesn’t biodegrade and poses a threat to animals who may mistake the foam material for food, Environment Texas Executive Director Luke Metzger said Monday outside of Whataburger’s headquarters on the North Side. Estimates show Americans dispose of 70 million foam cups a day, Metzger said.

“We think that they can find a good solution that meets customers’ needs but moves away from such harmful products,” Metzger said.

Company representatives have agreed to meet with environmental groups Dec. 19, months after activists first began petitioning the fast-food chain to eliminate its use of foam cups, Metzger said.

Monday’s event was more of a symbolic delivery of the first few printed pages of the petition. The full petition — and its 1,600 pages with 53,000 signatures — was emailed to the company.

Several fast-food companies in recent months have bowed to pressure from consumers and environmental groups to stop using single-use plastics and polystyrene foam cups and containers.

McDonald’s pledged to phase out foam cups by the end of the year. Dunkin’ Donuts said earlier this year it would replace its foam cups in favor of double-walled paper cups by 2020. Starbucks Coffee Co. announced plans in July to eliminate the use of single-use plastic straws in favor of strawless lids or straws made from other materials by 2020.

“Companies are very conscious of their brand,” Metzger said. “They’re, of course, wanting to keep their customers. And that’s why I think we’re going to see companies like Whataburger hopefully join the ranks of McDonald’s and Dunkin’ Donuts and do the right thing here.”

Carye Bye — an artist who moved to San Antonio from Portland, Ore., in 2016 — wore a hat fashioned from disposed Whataburger cups and containers she found littering San Antonio streets and sidewalks. Bye runs an Instagram account that shares photos of used Whataburger bags, cups and fry containers she finds while cycling around town.

“San Antonians love their Whataburger, but they don’t really think of the danger behind their favorite symbol,” Bye said.

Bye later added, “I want people to be aware when they pick up a drink and enjoy that drink, that cup that they’ve used is going to stay around a while. It’s not worth it.”